Benjani Mwaruwari, in Manchester City colours, tackles Dean Whitehead, then of Sunderland, during City's 2-1 win at the Stadium of Light in April 2008. Photograph: Laurence Griffiths/Getty Images

Sunderland were belatedly able to confirm the loan signing of Benjani Mwaruwari from Manchester City today after the Premier League was given proof of the technical problems which prevented the necessary paperwork arriving before yesterday's deadline.

In what may be a first, completion of the deal rested on an engineer confirming Sunderland's claim that the collapse of the entire communication network at the club's training ground on yesterday afternoon had prevented them getting the required information to the league and Football Association, even though they had everything signed off before the 5pm cut-off point.

Sunderland's manager, Steve Bruce, had called for "common sense" to prevail after the club were unable to send faxes or emails, and the league obliged, saying after its investigation that "everything was in order and the deal done before the transfer window closed".

Bruce said: "The paperwork was lodged but we had some huge, huge difficulties and we informed both the Premier League and the FA at the time of those. It was well in front of the deadline when we got the green light to get Benjani in on loan.

"He's a big, strong, powerful centre-forward and one we've been tracking for a long time. I'm delighted we've been able to bring him to the club. He'll bring another dimension to our striking options and will be a great addition to the squad."

This is the second time that Benjani, who has joined Sunderland on loan until the end of the season, has completed a transfer after the deadline. He also needed special dispensation from the Premier League when he moved to Manchester City from Portsmouth two years ago after he missed two flights to the north-west.

The 31-year-old is Sunderland's third signing of the winter following the right-back Alan Hutton, on loan from Tottenham Hotspur until the end of the season, and the centre-back Matthew Kilgallon, from Sheffield United.

Sunderland had completed the signing of Hutton in plenty of time yesterday but the transfer of Benjani was more problematic after talks broke down over personal terms at the weekend, only to be revived late on deadline day.

His signing will be a big relief for Bruce. Although Darren Bent has been in excellent form since a £10m move from Tottenham in the summer, with 15 goals this season, the manager is worried about the lack of cover for his top scorer and also wants competition for Kenwyne Jones. The Trinidad & Tobago international's form has dipped following a month of intense speculation linking him with moves to Liverpool, Stoke City and Birmingham City, and Bruce admits the player has been badly affected.